A attempt to compare two theories on how to change and maintain healthy dietary and exercise habits in African-American adolescents. African-American adolescents are at particularly high risk for developing high blood pressure with no evident organic cause and heart disease in early adulthood. Primary prevention of these problems must be a priority to reduce the rate of illness and death in the African-American community. Increasing evidence suggests that dietary modification and exercise strongly influence the development of such illnesses. The purpose of this study is to compare the capability of two theories of promoting and maintaining healthy dietary and exercise changes in the African-American adolescent. The study will recruit subjects at schools and will involve 1200 black male and female adolescents. The study will last for five years, each subject will be enrolled for 18 months. Each subject will be randomly assigned to one of three programs. The first program will be Social Cognitive Theory (SCT) which allows for support and influences from social factors, positively promoting behavioral change. The second program will be SCT plus motivational intervention which creates a consistency with beliefs and actual behavior. It's based on the proposition that one's public display shapes a person's private self. How a person presents himself has a powerful influence on how he comes to perceive himself and consequently behaves. The third group is a control group. The 1200 students will meet three times a week, three hours each time, for 12 weeks. At a baseline visit, medical history and demographic situations will be discussed. At the baseline visit, the post-treatment visit, the 6 month follow-up, and the 12 month follow-up, motion sensors, exercise records, blood pressure, skinfold measures, height, weight, urine electrolytes, diet records, SCT variables, and motivational variables will be assessed. Interview questions will be answered to see how effective the strategic self-presentation manipulation was. Participants will be taught by a registered dietition to control and record their intake and exercise. The control group will maintain it's usual diet and exercise patterns. Some special activities will be provided to the control group such as computer skills, sports management skills, health related arts and crafts, and observing African-American dancing.